Separation and chemical differentiation of α and β subunits in yeast phosphofructokinase

The two types of subunits α and β constitutive of yeast phosphofructokinase have been separated by ion-exchange chromatography under denaturating conditions. Amino acid analysis and peptide mapping were performed on the isolated subunits. The frequence of most of the amino acids significantly differs between the two types of polypeptide chains. Moreover, tryptic peptide maps of α and β subunits are clearly not superimposable. These chemical differences seem sufficient to account for the distinct catalytic and regulatory functions of β and α subunits in the yeast phosphofructokinase reaction.